HUBBLE SPACE TELESCOPE

                       DAILY REPORT #2459

PERIOD COVERED:  0000Z (UTC) 09/16/99 - 0000Z (UTC) 09/17/99

Daily Status Report as of 260/0000Z

1.0 OBSERVATIONS SCHEDULED AND ACCOMPLISHED:

   1.1 Completed WF/PC-2/STIS/CCD 8256 (Deep Helium-Mixing and the Ultraviolet
Spectra of Hot Horizontal Branch Stars)

       The WF/PC-2 and The Space Telescope Imaging Spectrograph (CCD) was used
to make observations of globular Cluster NGC-6752 in order to study the deep
helium-mixing and the ultraviolet spectra of hot horizontal branch stars. 
There is now good evidence that the luminosities and gravities of hot
horizontal branch stars in globular clusters are not correctly described by
canonical models of core helium- burning stars.  A wavelength calibration image
was also taken.  The observations were executed as scheduled, and no anomalies
were noted.  

   1.2 Completed WF/PC-2 7251 (High-Resolution H-2 Images of Selected Nuclear
Starbursts)

       The WF/PC-2 was used to make high resolution observations of the H-2
region in the galaxy NGC-6441in order to study the molecular environments for
star-forming activity in the centers of mergers and interacting galaxies.  The
observations were completed as planned, and no problems were reported.  

   1.3 Completed Two Sets of STIS/CCD 8408 (STIS CCD Dark Monitor C8)

       The Space Telescope Imaging Spectrograph (CCD) was used to make a CCD
bias calibration observation.  This is to monitor the darks for the STIS CCD. 
The observations were executed as scheduled, and no anomalies were reported.  

   1.4 Completed Three Sets of WF/PC-2 8443 (WF/PC-2 Cycle-8 Supplemental Darks
pt1/3)

       The WF/PC-2 was used to obtain three dark frames every day to provide
data for monitoring and characterizing the evolution of hot pixels.  The
observations were completed as planned, and no problems were reported.  

   1.5 Completed FGS 8309 (A Link Between Massive Binary Stars and Non-thermal
Radio Emission)

       The Fine Guidance Sensors were used to make astrometric observations of
the massive Wolf-Rayet binary star WR90 and several nearby reference stars. 
Non-thermal radio emission in Wolf-Rayet stars is explained in terms of
synchrotron emission from shocks in the stellar wind.  The observations were
executed as scheduled, and no anomalies were noted.  

   1.6 Completed STIS/CCD 8409 (STIS CCD Bias Monitor C8)

       The Space Telescope Imaging Spectrograph (CCD) was used to make a CCD
bias calibration observation.  This is to monitor the bias in the 1x1, 1x2,
2x1, and 2x2 bin settings at gain=1, and 1x1 at gain = 4, to build up high-S/N
superbiases and to track the evolution of hot columns.  The observations were
executed as scheduled, and no anomalies were reported.  

   1.7 Completed WF/PC-2 7408 (Parallax, Proper Motion, and Spectral Energy
Distribution of an Isolated Old Neutron Star)

       The WF/PC-2 was used to study the parallax, proper motion, and spectral
energy distribution of the old neutron star RXJ185635.  The target is a bright
soft X-ray source in the direction of the R CrA molecular cloud.  The
observations were executed as scheduled, and no anomalies were noted.  

   1.8 Completed Two Sets of STIS/CCD 8406 (POMS Test Proposal: STIS
Non-Scripted Parallel Proposal Continuation V)

       The Space Telescope Imaging Spectrograph (CCD) was used to make high
galactic latitude observations taken in parallel with the prime science
observations as part of a POMS proposal.  This is a STIS non-scripted parallel
Condition V proposal.  The observations were completed as scheduled, and no
anomalies were reported.  

   1.10 Completed Two Sets of STIS/CCD 8545 (POMS Test Proposal: STIS
non-scripted parallel proposal continuation VI)

       The Space Telescope Imaging Spectrograph (CCD) was used to make low
galactic latitude, non-scripted parallel observations as part of a POMS test
proposal.  The observations were completed as planned, and no anomalies were
reported.  

   1.11 Completed WF/PC-2 8457 (UV Earthflats)

       The WF/PC-2 was used to make a ultraviolet Earth flat calibration
image.  This is to improve the quality of pipeline the ultraviolet flatfields. 
The observations were completed as scheduled, and no problems were reported.  

   1.12 Completed WF/PC-2 8444 (WF/PC-2 CYCLE-8 Internal Monitor)

       The WF/PC-2 was used to make a bias, and an internal flat, observation
as part of a Cycle-8 monitoring program to monitor the health of the cameras. 
A variety of internal exposures are obtained in order to provide a monitor of
the integrity of the CCD camera electronics in both bays {gain 7 and gain 15},
a test for quantum efficiency in the CCDs, and a monitor for possible buildup
of contaminants on the CCD windows.  The observations were executed as
scheduled, and no anomalies were noted.  

   1.13 Completed STIS/CCD/MA1 8032 (STIS GTO Observations)

       The Space Telescope Imaging Spectrograph (CCD and MA1) was used to make
long slit spectrographic observations of galaxy NGC-4194 to investigate the
stellar population and interstellar environment.  Imaging of galaxies with
WF/PC-2 has indicated the presence of knots of blue stars in many galaxies.  A
wavelength calibration image was also taken.  The observations were completed
as planned, and no problems were reported.  

   1.14 Completed Two Sets of WF/PC-2 8436 (POMS Test Proposal: WFII Backup
Parallel Archive Proposal II)

       The WF/PC-2 was used to make archive observations parallel to the prime
science observations as part of a POMS test proposal.  This is a POMS test
proposal designed to simulate scientific plans.  The observations were
completed as planned, and no anomalies were reported. 

   1.15 Completed WF/PC-2 8090 (POMS Test Proposal: WF-II Parallel Archive
Proposal Continuation)

       The WF/PC-2 was used in the parallel mode to make some high galactic
latitude archive observations.  The program will be used to take parallel
images of random areas of the sky.  The observations were executed as
scheduled, and no anomalies were noted.  

   1.16 Completed STIS/MA1/MA2 8425 (MAMA Full Field Sensitivity Monitor & PSF
Check)

       The Space Telescope Imaging Spectrograph (MA1 and MA2) was used to make
observations of globular cluster NGC-6681 as part of a MAMA full field
sensitivity monitor and point spread function (PSF) check.  The purpose of this
program is to monitor the sensitivity of the MAMA detectors over the full
field.  The observations were executed as scheduled, and no anomalies were
reported.  

2.0 FLIGHT OPERATIONS SUMMARY:

   2.1 Guide Star Acquisitions: 

                            Scheduled Acquisitions: 4
                                        Successful: 4

                         Scheduled Re-acquisitions: 11
                                        Successful: 11

   2.2 FHST Updates: 

                              Scheduled: 12
                             Successful: 11

       As documented in HSTAR 7257, the full maneuver update at 259/163817Z
failed due to the error box results for tracker 1.

   2.3 Operations Notes: 

       Using ROP SR-1, the SSR EDAC error counter was cleared three times.

       The NICMOS FPA temperature sensor for detector 2 was enabled at
259/1534Z.

       The SSR engineering pointer was set at 259/2001Z per ROP SR-3.

       An SI C&DH error was reset at 260/0308Z in accordance with ROP NS-5.

3.0 SIGNIFICANT FORTHCOMING EVENTS: 

       Continuation of normal science observations and calibrations.

/DMH